SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bf92958f9d7bb4d75e0c45c3d9ad1680d512ef115df4098de33bd0ca294e8ca' 
  AND token = '0dfpdM7QpcPI21QBCrN5dMOzBO/oR/FXBEWcrgIYuRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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