SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ae454b26b133eb80ff5233ae985cf2f74be05e57e7fd50ff03030c8839e97002' 
  AND token = 'urmBB4+CSfw7CKNVD0GQsTP7c2PQNwdacBKZ3jnGrKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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