SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'abf5158c2818be047ff63b392a9cf53faac23e48ce012a91b779d4f430602f02' 
  AND token = '2PNvsizzrPBAIv/1EqcfuGa+A4YgkiBNy3bwfMuQB2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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