SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '583da29444c181195b49f15ae897b5afa35058ed4b58ca4912d6209fe381b178' 
  AND token = 'MMNqsfc8oXgwKxn/g/KjkYQzKWRy0iy+SCaYHGOorbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00111

JSON explain

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