SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47f1b5311944d81d69901d2bc4a3dfb7c1819139a0a15d80f363bef4d090d631' 
  AND token = 'wvTceUdAoWRjJ2V134By36iV3zyYfokTwbEK1QBlYjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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