SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0a7d0350287eeca66891c03c34612a4e4c8f904eba34d54d70893de962b30e8' 
  AND token = 'sEZEF/23ba2MoyefcrMgOSJGyVp/LFlW0i0lKodl3Kk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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