SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32d2a1c29b0fd0246457ff5357172b9f462cc3f4c3388646dc66cdaeb25c574a' 
  AND token = 'iI9kBemyi/X24QVwz0pGxnYbMJoTVJli+DL0HI7ZNk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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