SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2f847ed99f27b55a4b0ef396722da184c6d6ce3d2907526954c854b7273ebaf' 
  AND token = 'vWWP0CjRPLrbFXJoG/vGLmzH8vAQgPF8Ryb7M0HJcNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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