SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1b418afe9ab320de00f09b0713cb5859187ad7ff8555ad07e116e4955c35790' 
  AND token = 'pJgpiM354WcBH8vPkQWm4EeGqr0+9aqXW6EW26UM+vk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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