SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09ecc9ee8b50a943ceda21d29bb810a2a5c3c26c30e424d069957fa97191736c' 
  AND token = 'F+gj54n4YIJPPqWzuTiPWZRLnTFwu7paR9cwHws/z1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}