SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a3befae77125f4c2b890ce8867a393681669466311746571c0f6650c9a7165f' 
  AND token = 'pD7ULXR5mAVRJVjCZV69UsUsc4+JdY372VvYr0hiSK8=' 
  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"
    }
  }
}