SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4344c5a99eb9dc63477b52414fb93938c9d5aae415efa3af19988c13a1cc82b6' 
  AND token = 'll1/oK/GUS13x77gZPsmXi9OyJ6SOpTHh9ufkpJhGcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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