SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcc24c91b4f37f7b71ee40047e9619eb348098fc2c3c448c8ea66b130cccc3cb' 
  AND token = 'gmmQohRm86yVGRpdj/0pwC0HBfvPuYarmwJqDZlz45Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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