SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a4ffa958d6d4031a475e479d57baeefe74d53f5eaae536889b4ba532b3a8a39' 
  AND token = 'sX23Qz2O3ykAc5Sle0vHAC4XZ9MBqQMutIlGn5znqH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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