SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7730bb29aafb1d6abe1953e0dff867944cabc80cb18e526c3ff91089646b4b0a' 
  AND token = 'yrkr/ZCIMMqutdA5He7u5fXRDweddqxGVjm4O9Gszqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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