SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e403568ab0f598edf82c26dba0023cc06b069ca4263069cff3ac3ea0064acf7' 
  AND token = 'oiKFM5woGjjpVhj/qXrO265uvFofyxnQBvXgV2J9D/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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