SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c51239d8ca7c442d27c2cb9bfa9afc62e6ac2f1aa870b9181673544f64798b3' 
  AND token = 'nUeBBxws+xWnoz6js4IkVs7aO2rf2XMhB6qUAwTulTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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