SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ba627e938b3ca7233e17f4eedaddd368c803c3c09f135d7aa35e1ba2495bc7d' 
  AND token = '6hGY75G4jNFUEN+mKX/mg10UGfSgbRLk/iqz1mJuTGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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