SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c51f204fc626378dfdbfa700714da6601c2c35347584feee00f00b6230e0700a' 
  AND token = 'KOfNJD9xcT5c9jxDD7hYvavXwb3s6gwYWMFSbZC8iCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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