SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '255918bb2f52ba9f449badaf2b402bdd1ef58a2166f43dbf14f262420836ea7f' 
  AND token = 'cwx1Tp+9tmNgKJRQGjBj4f/j9jFbryXHUafrhyFgqQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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