SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2e3fe571eabb2388131f39479a1d4b49380237e829993a7058a416b3ad3195b6' 
  AND token = 'wJ3WGETDNtt2gjSkKJlBw3nmVCtfsPS7iXRHP0+Fo9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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