SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c9c646a8a527ed01f0a7b76d69be38ac843175b6edd3381fcd4392f3b9f892f' 
  AND token = 'ZNiuFaL3UJQJEeqvXUektlS/MQ7805OAHprxlOwWCqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}