SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '936fee3427ffa5913ea9486ac92ab98f1bf49c977b80d139a1f1b1756315da14' 
  AND token = 'OjDkCmClaRqzrm2BMGX56CGKEhOmRzb5pL2ZupEqOlE=' 
  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"
    }
  }
}