SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '5fb30efda17c53f35b05f55dd8374c1fed2bcc8d204357ba7cb912240aef139b' 
  AND token = 'LwXovSUDmBICGE67RRLEihRfXVNIyvrg0MBMfNIqB88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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