SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6903d926a071473b8ef959448980d63cdc97e243b9b4f507d9ccb7e95451076d' 
  AND token = 'o7BvIsngw6yKb8rmuSvBJ6TdJ1LXQTG7L0x/RgGoJVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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