SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddc3432f71e11951863b55629949c174a0049f356f8087adb830ce3bb4e37ec1' 
  AND token = '/UONQvYAjf5T5hSA/MVKiOB5KGQk1IXrIlxjCO6llh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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