SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd77a68a09ea9f1f893c5a6f6962981b1f2e625b26e7214423bd229f090c7c425' 
  AND token = 'uKHRyvZsOdf+oxoBpZ9WB4u44irXgaoM62dCnX5n3/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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