SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8686c900c8a3fba385a6ab5d2d5756be64d99880a68c288ea62c69e512f17679' 
  AND token = 'PdJfC73nYm4H5BH0ynDHlch4mRsIaTjRn4gUv1HNl5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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