SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c68424591f6784d3fc73ec7ebe35e948647d4e19e0381190ea83bc1dd03f7c85' 
  AND token = '2mLsgDOXw3zHRtxLms8njN66MbjG4aOyKBJLs1FJYvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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