SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49127be37dcc2e498d140483c7ceddebfa8eb8cddae718cadfc8497dfb4b350e' 
  AND token = 'JDW+I3JnIRzUs8GM0XSceqhlyN9P7SGCL2lxrhYsh00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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