SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeeedfb6c96b825cf78c44304c0279fc89d56447046c4124cf727e6d96e35450' 
  AND token = 'ZqSlL6RZptA8m+ZADmmujRvk0YXaSMTW8eLZ3hjuOaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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