SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e31ce322635b7a26b288bbb595dd779c3473355a696e5313eaebd9b82dbfdf77' 
  AND token = 'sYjvQ/k/aLastVY23bs9tUwgGFUYbo3127hQUDh0XYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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