SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61a12d1bdcd6ada8939d4041627ffc8b0f3250395f4d10abbf301865839af584' 
  AND token = 'G32wGT4HMsCQT+bgrE9LHJBbATLeRhUBZKUK+DTuNw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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