SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbf2df0a7abcb28cddc280f43cb1801bb35299ed4d9d982fcacf672ae494ae68' 
  AND token = 'O8Zgu/xbWHKDQuLw4QNGDypYGyfl4gUhvhnIQUq9zeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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