SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71499b97bcccd71cb78f7a59c663701107195e5b95d2b753a2267727c8188365' 
  AND token = 'rDN2GXp356d2lUScIB5aRv8fT3yJIsy1IkulH9gu8Qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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