SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8d4334223dcfc9cb1b30df949f505c14ac379e50774e6634a9134a2930205e1' 
  AND token = 'xhKScA9WG+qBq9w/xI75Ho9ZT+OWIIcvAizz+4o1lRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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