SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8163a08b22462aa72f1399521e9ec21b6ebf27ddd131b937eb016dc69f5923a' 
  AND token = 'cUTJefkMbLpNCRYVGzCP0LOR0IH5AS9RR3W9Bf/NOA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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