SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54ac94b1e462ef2890e6d734ca850543e7f70e63c94e5b94902b886480bf2cf1' 
  AND token = 'Bgw9mJugi2gwRjpmvnaBAXZj8vHJF19ROP3MKGorGas=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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