SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fffa6fa48cdcc9fb09f9512c160afdb4de2056898f4b58c02589374194320a0a' 
  AND token = 'X36cKDn8QNCu+fl7rluMmRgemDLwFZnKHVUYXtkGOlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}