SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ceb09fb1841f12169d8ecbd2c9fe6a84fd01ea9da8e2def6004a1780838a27af' 
  AND token = 'aVGcqsaynY55C2WBTJXFrlcz1LM69eCyDxTnTLwHshs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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