SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff89707c0f47839befbf28be042c8b9832ca0af64d1f1513b5d0603b76ef688d' 
  AND token = '38Jap7Jn+FsUT+7gLhu6rKbGSB0NP9D4pPvbVXovv/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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