SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59709576f972914bd999f3fc9b43a7e4277055093c5546d061d6eb89dfc5d5f0' 
  AND token = 'dluyl8rjgFKeh2F9h7pBUSsFAxYWhiO91AxwXMwF0vM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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