SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11c2167c4b070a1087b8df9bd241a999eb902ad899afc706cf5faf94ba1b756e' 
  AND token = 'FlR6zKO4ulPYIEQOSlrJq/v7VbHVNoFBYeBpAHj/HE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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