SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31e357235dafa5bafd8e3254e81ab507dbf1f9eb66e56521daafc1075955156e' 
  AND token = 'RA/B8BqDXDf05/GxKiXBRVs4YYZD3TWwIkLvVz1/gDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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