SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '580fdc3e18682cbaa338e73f4417b0806f2622ad9f2653d394d723a2d83a8043' 
  AND token = 'pRatfp2n1AxLtEHBaY5uPeUfKE5aygva6LF8hfc9GSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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