SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a9266aae727ef4fb71aea5c75b4da908c0c426618966c0d8f8b8330872bff5a' 
  AND token = 'OlcK5UaX3Ihng6iGcvdtIgR6yLlpiV/qCRbPABj8QBE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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