SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4591572af150f0615c4ce7ccbdc66c0122183463cd46a4214726776ba98999a' 
  AND token = 'XgJ4hZzY37NfIkXaEFNLqhF3IyK7XHDIC1KIVLDcw+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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