SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c29a0adf870a0623f75dbbf64b6ee91c30bd7dd164dd9d776890076d87aff67' 
  AND token = 'p1y+VjXJtybDOaWwCXBs9/MqHKxev4QCXeVYqixsgKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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