SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fce12396ff9fcd8dd36b3580d076a9b3cf15a65359b913b0870528ab5430ebb4' 
  AND token = 'N1WbNjgNj6Un3b+XstBSA+muN9wLE1a7eUWz2opANEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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