SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '936b6e2930a09f3f3892bbae46674258452645ee2042cb3baa711f53c38c781f' 
  AND token = 'fEzYKysouFjsPMqgnWv/JHuws7HlZfCD7yzUzDKJzq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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