SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efc4f6dcfef4874eca74454cb7ad546cf4896aeeb102059ac78939e00d0092f8' 
  AND token = 'VKfS1iOIT4yYxN13i+GzVQskVn+u5kkBIUf8HQRBjE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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