SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dab348e36b840352962f822cf98ab0a5cb06bf6f31ce8626f78057b737fc108d' 
  AND token = 'PbmQGF9F1fKDM8y9bLhf4Un/FnfMuIw6dKH0VgW5xb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}