SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd96eaabaca82fa8096af5f1236cf90c0eafd7db8c762391d675079b1d6eee2c6' 
  AND token = 'F8AEXD7613cYiIy1O2NhA1tMjXTrwEJk5JcCiUVR/7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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