SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a19a723d27962624c4b82f7bc1e236149937e028d7c70a2973844798cde82e6b' 
  AND token = 'ggWzIBrMu4pPDQTjx2K76cAp5K0r0Snudh36D/LYrhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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