SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c67bbfa9a89ac31ee8f1283b7433be1365e087a633877da11399f3bbb525db25' 
  AND token = 'BZG4EdJfPOQun1RDgRhBCHn+5aBdrf0JIVONEmdUrwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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