SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67c3a2fcd0316feffd6d48d98b510e8ec6e5735c14782cd06d11d2e2e065d2eb' 
  AND token = 'SDCwwRfW/qTBbarEFlOVaLWoo/pZNSe+jIsbDd50xHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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