SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a98ab583507b296b893dce83e1cd115e28329d5d1cfea199f618684a80b8cee' 
  AND token = 'p7NFPus9ZmGnC/vyKJC/8KvoLh0JAG/W8hT6OZxchfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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