SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9af092c6dcb4962b96d850e1046d0e29be54cc3b7a51687c198a00b2c7824f10' 
  AND token = 'D6eYPerZKXj9820WhWstkOP2fXBrRyPHtqZRWS894ME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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