SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed0b58ea6174261f7daab5b9f21424d4c172960849b7a16bfe74ef50acfe1c9c' 
  AND token = 'A2yBl7SQEeJ4TliMOA+rCl6T/dyrgrWkEaEZ8BTDY1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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