SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffdb951c765c4236be6b0bba9a3238296fe1ad32ecd95c7df7aa11d136833aab' 
  AND token = 'FBwj3N20aBNZJDN4ZiCEfBna79bsYOTcjuLTjPM1wA4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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