SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f60668b44aa534ee240d2599c1806beba8574b6353ef185a19a74fed2db23cdb' 
  AND token = 'CCtW/WaxBhnqzRigItDHKaNVS5/UGKJv0Ma+7qpQUSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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