SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'fc2da828e4697ffa9f00c27febdbc11804401bf2ecdd5dbf54c3896cfd52783f' 
  AND token = 'XT/aNPXzVEXMFV/G8nmJIwY1i/Pw0Ut8vwpgRrKEkIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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