SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1990473da487aa7821757025a4ff54eca413db7b08b6db826d13ea733a45cd8c' 
  AND token = 'kqDlbB5n54r8cqxj3xJfLDIXAzuIN/K2rWqsPHjHDb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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