SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9e7d25e20d214110f5b299bb97d5e7fdc55896bf35baa0a44c2323780be1eba3' 
  AND token = 'pMyqtHlUXXi9nNMlj6i4llbeMusoES+zdhJ+XyMQdVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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