SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c14baf5d20a3db0b5e649f03a85a0eaee5bf946767ad717df4e01db31a12206' 
  AND token = 'wnLWFiO4CvLqJzcAKJJCrKoB+QNCd1cBA5hZdaJKBuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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