SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '153b58ce4295c868f5095de27a0a94a327bd974ab1f21b3df418facf7bf69de6' 
  AND token = 'U4K8owzmMKV6/D6O6UqWRzHbIYhxuyxREGlctKOeVvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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