SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e7e4d300e4fb5760f5119feda97d4449f0058c70e08db51b21344b933fe593a' 
  AND token = 'bohKk7TwZUDQAsiwfB0hcNAPeghOgPkW0PEwIG1CMiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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