SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '448197430987705e99907fddc0472f2f07128b7ade491844fbc600f6e25711c1' 
  AND token = 'cjzdS0KsHgA3ilYRvXbgI0uz3dImI5gDjpF8JBvAoGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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