SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20defd2f399692dad5196bf146c39ce4c63108cd0e4f5fcbc523e5b8a39cb593' 
  AND token = 'zgj2NylErN2QYl7U5JSCEhs5K/vOUVtrltDUVLHpV3E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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