SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9cab42aeb9807241dc41a7a0447de45613eb5d07829056a10a47dcca060e19b' 
  AND token = 'RuSbyvlqgWq8CyAgV5v6aYllYcZJSEVJG1p68EZgO60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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