SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85cf0dc96f605e2a7c311e176fa2fe58547c2b775ed199ea5ad2d566f3e7d61a' 
  AND token = 'FK3zZlSm+PNZgGbYJGPNyx2CQDEdmdzprzLb8pz5RaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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